The present invention relates to a container for the packing of two compositions which must be separately kept until being mixed shortly before use.
Two compartment containers have long been known. Normally, they consist of two separate chambers which are arranged one upon the other in a packing unit. The upper chamber is provided with a closeable orifice for the delivery of the mixture. Both containers are separated by a separating foil which is penetrated by a sharp-edged punching tool in the container, when the containers are screwed or pressed together. This allows the container contents to mix shortly before use. Such a two compartment packing unit is described in German Pat. No. 2,760,079.
Further arrangements of known two compartment containers are disclosed in German Offenlegungsschriften Nos. 2,451,167, 1,536,305, 2,211,753, and 2,539,231, U.S. Pat. Nos. 3,521,745 and 3,548,562, and German Utility Model No. 7317067.
The filling of two compartment packings with the compositions to be separately kept until their use is normally effected in such a way that first the bottom container is filled with the corresponding product, then its opening is welded with a separating foil to the upper container which is then filled and closed. Such a procedure consisting of several steps is rather complicated and expensive.
Another disadvantage of the known two compartment containers is that the opening mechanism, i.e. a mandrel or a corresponding cutting edge causing the penetration of the separating foil, has to be fixed in one of the two chambers and is thus permanently in contact with its filling. This might cause unwanted modifications of the product when it is stored for a long time. Thus, there existed a need to develop a two chamber packing which does not have these disadvantages.